On a OMAP-L137 target, running Linux 2.6.37 on ARM core and DSPBIOS 5.41.3.17 on DSP core,
an acquisition system is running, supported by Issue/Reclaim transfers according to DSPLINK is 1.65.00.010 version, which is based on SHARED RAM.
The DSP application is running a thread issuing SIO_issue/reclaim pairs for an OUTPUT channel.
SIO ops have a timeout of 1 s.
The output buffer issued is mapped @ 0xC1F30880, size is 0x5000.
The ARM application is running a thread issuing CHNL_issue/reclaim pairs for an INPUT channel.
CHNL_ ops have a timeout of 200 ms.
The input buffer reclaimed is mapped @ 0x40126880, size is 0x5000.
DSP output buffer is transferred to ARM input buffer roughly @ 64 Hz / 16 ms.
When the input buffer is available a second thread sends it to a client application running on a PC though TCP/IP.
On most of our boards the system works nicely for days.
On some boards (identically configured as HW/SW) after some time the ARM core hangs,
i.e. the Linux operating system itself does not respond any more.
When this happens:
the DSP core is running safely, only a timeout was recognized for the SIO_reclaim call.
After the timeout , DSP core code prevents further SIO_issue/recalim calls are performed, but the channel is still operational.
On the contrary, the ARM core is freezed just after the CHNL_reclaim call is issued: the call itself does not return.
Hanging means that the Linux kernel itself is no more working.
The fact that the hang happens in "faulty" boards if and only if a CHNL_Reclaim call is issued, could lead me believe that this is SW problem.
The fact that "working" boards NEVER hang, (and "faulty" board can work for a substantial time) leads me to believe that this is an HW problem, related to SHARED RAM management by the ARM core.
1)Is it possible that some OMAP-L137 device have a silicon bug on SHARED RAM?
2)How to address this problem ?
N.B.I tried to compile DSPLINK on ARM side with debug option, but the system slows down too much.
N.B. In no way I could enable selectively the different debug levels
I will send anyone whishing to support me whatever information is needed.
Thank you in advance for your attention.
Misha
